Each day a different image or photograph is featured, with an
accompanying caption, which deals with various topics in Earth Science.

Sundog Above Taunus, Germany

This handsome sundog or parhelion was seen shortly before sunset on July 19, 2007, near Taunus, Germany. Sundogs are the most commonly viewed halo phenomena. They're often observed when cirrus clouds containing hexagonal ice crystals are in the vicinity of the Sun. Look for them at the same elevation of the Sun but 22 degrees to the left and or right. The sundog shown above is to the right of the Sun, and its reddish color is due to the fact that the Sun is low in the sky. The longer path length of sunlight extinguishes the shorter blue and green wavelengths.